1. Field of the Invention
The present invention generally relates to a wireless signal transmission encoding/decoding method and device, more particularly, to an encoding/decoding method and device utilizing a baud rate to encrypt data for transmission.
2. Description of the Prior Art
A remote controller is frequently used in daily life. Its application can be found in many fields such as car security, house security, audio/video equipment, and other appliances. In such applications, the remote controller is used for convenience. Although in many applications, security is not a major concern, it is a critical issue in other applications such as in a car security system, home security, and TV channel protection.
In general, the remote controller system can be classified into two categories: one-direction and bi-direction. In a one-direction remote controller system, a transmitter simply transmits a control signal to control equipment in a remote location. While in a bi-direction remote controller system, a control signal is transmitted interactively between a transmitter and a receiver. The bi-direction remote controller system is much more reliable for it employs the function of mutual authentication. However, since it is complex and expensive, it is seldom used except in some certain cases.
In a simplest remote controller system, the control signal is formatted in plaintext and transmitted wirelessly to the receiver. Since the control signal is transmitted in plaintext, it is so easy to be eavesdropped and modified by a hacker, so the system is extremely unsecured. A common example seen in daily life is when someone uses a remote controller to open his own garage door, he opens his neighborhood's garage door at the same time.
As technology for security advances, there will be more and more remote controllers transmitting signals in encrypted format, which means, when a remote controller is transmitting signals, the signal is separated into plain code and encrypted code. The plain code is in regular format, comprising a fixed data structure, while the encrypted code, in transmission, is encrypted with certain mathematical algorithm and is difficult to be decoded by a hacker. The concept of encrypting a signal for security is not difficult to understand, however, the practical implementation is quite complex, and the cost is relatively high. The present invention discloses a signal transmitting method and device wherein a plain code and an encrypted code will be encapsulated in one single signal. An application can be seen where the plain code is used in a public entrance security system such as a community gateway or a public garage door that only needs the plain code for identification, while in a different application such as a private garage door security system, the plain code and the encrypted code will be verified at the same time for strict authentication.